This advertisement (or image from an advertisement) is in the public domain because it was published in a collective work (such as a periodical issue) in the United States between 1929 and 1977 and without a copyright notice specific to the advertisement. Unless its author has been dead for several years, it is copyrighted in jurisdictions that do not apply the rule of the shorter term for US works, such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties. See this page for further explanation.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
This work is in the public domain in France for one of the following reasons:
Its author (or the last of its authors in the case of a collaboration work) died more than 70 years ago (CPI art. L123-1) and did not benefit from any copyright extension (CPI art. L123-8, L123-9 and L123-10)[1];
It is an anonymous or pseudonymous work (the identity of the author has never been disclosed) or a collective work[2] and more than 70 years have passed since its publication (CPI art. L123-3);
It is the recording of an audiovisual or musical work already in the public domain, and more than 50 years have passed since the performance or the recording (CPI art. L211-4).
Please note that moral rights still apply when the work is in the public domain. They encompass, among others, the right to the respect of the author's name, quality and work (CPI art. L121-1). Attribution therefore remains mandatory.
↑Copyright extensions must be considered only in the case of musical works and of authors Mort pour la France (died during conflict, in the service of France). In other cases, they are included in the 70 years post mortem auctoris length (see this statement of the Cour de Cassation).
↑The collective work status is quite restrictive, please make sure that it is actually established.